Most, if not all, prosecutors deal with pretrial publicity. And most may think that past experience has prepared them well for the onslaught of television, newspaper, and online media outlets that will converge on a mass casualty homicide. Anyone that thinks that is almost certainly wrong.
The local police chief, sheriff, and FBI Special Agent in Charge (SAC) will likely want to give a press conference, and they may invite the elected prosecutor to participate. Unlike most other cases, there will be detailed briefings for civilian government officials (the President of the United States was personally briefed on the investigation in our case), and some of them may talk to the press. A prosecutor on one of these cases quickly comes to realize that the only people who need to be briefed on the case are those individuals who have an operational need to have the facts, or put another way, people who are actually working on the case. So, the prosecutor should, if possible, limit briefings given to civilian government officials, or even law enforcement officials who are not working on your case. The risk of improper and anonymous statements in the media is directly proportional to the number of people briefed on the investigation.
Apart from limiting briefings, there are certain things that a prosecutor can do to protect the integrity of the case. First, the prosecutor should immediately pull the local rules on pretrial publicity, which in most places will be based on ABA Rules of Professional Conduct 3.6 and 3.8. RPC 3.6 generally prohibits "extrajudicial statements" that an attorney should know will "have a substantial likelihood of materially prejudicing an adjudicative proceeding..." The comments to the rule provide specific examples of what not to say, which are often the very things that the press is most interested in, for instance the past criminal record of the suspect, or statements made by the suspect, or what evidence has been collected. Anyone giving a press conference or interacting with the press needs to know these limitations intimately.
Additionally, Rule 3.8 prohibits making "extrajudicial statements that have a substantial likelihood of heightening public condemnation of the accused," and mandates that you as a prosecutor "exercise reasonable care" to prevent the police who work with you from making such comments. This means that the prosecutor is to some degree ethically responsible for improper statements...